Field of the Invention
The present invention relates to a substrate processing method and substrate processing apparatus which can shorten the processing time.
Description of the Related Art
A substrate processing apparatus performs processing using dummy substrates to condition the atmosphere in each chamber before and after processing a product substrate. When, for example, a plurality of product substrates are processed in each chamber in the order of chamber A→chamber B→chamber C, the same processing is repeated for each chamber. Thus, processing of transporting dummy substrates to condition the atmosphere is performed for each chamber before the first product substrate is processed and after the last product substrate is processed. Note that Japanese Patent Laid-Open No. 2004-153185, for example, gives an example of such processing of conditioning the atmosphere using dummy substrates.
However, product substrates are often processed (their return processing is often performed) using the same chamber by a plurality of times under different conditions.
Assume that product substrates are processed in each chamber in the order of, for example, chamber A (first process)→chamber B (second process)→chamber C (third process)→chamber A (fourth process). In this case, return processing is often performed so that product substrates are processed in chamber A in the first process, and processed in chamber A again in the fourth process. In such return processing, when different types of processing are to be performed in the first and fourth processes, processing which uses dummy substrates is necessary to condition the atmosphere in chamber A before and after each of the first and fourth processes.
If return processing is used as in this case, when dummy substrate processing for conditioning the atmosphere in chamber A is executed for each product substrate, the number of dummy substrates increases, thus degrading the processing efficiency.
It is an object of the present invention to provide a substrate processing technique which reduces the number of times of wasteful dummy substrate processing even if return processing is necessary in product substrate processing, and is therefore excellent in processing efficiency.